LBJ2.learn
Class Sigmoid

java.lang.Object
  LBJ2.learn.Normalizer
      LBJ2.learn.Sigmoid

public class Sigmoid
extends Normalizer

The sigmoid normalization function replaces each score xi with 1 / (1 + exp(-alpha xi)), where alpha is a user-specified constant.

Field Summary

protected double

alpha The user-specified constant described above.

Constructor Summary

Sigmoid()
Default constructor; sets alpha to 1.

Sigmoid(double a)
Initializing constructor.

Method Summary

ScoreSet

normalize(ScoreSet scores) Normalizes the given ScoreSet; its scores are modified in place before it is returned.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

alpha

protected double alpha

The user-specified constant described above.

Constructor Detail

Sigmoid

public Sigmoid()

Default constructor; sets alpha to 1.

Sigmoid

public Sigmoid(double a)

Initializing constructor.

Parameters:

a - The setting for alpha.

Method Detail

normalize

public ScoreSet normalize(ScoreSet scores)

Normalizes the given ScoreSet; its scores are modified in place before it is returned.

Specified by:

normalize in class Normalizer

Parameters:

scores - The set of scores to normalize.

Returns:

The normalized set of scores.